Hydraulic grinder



Sept. 13, 1932.

S EINSTEIN ET AL HYDRAULIC GRINDER Filed July 29, 1925 5 Sheets-Sheet l Sept. 13, 1932. s E|N$TE|N ET AL v HYDRAULI C GRINDER Filed July 29, 1925 '5 Sheets-Sheet 2 gxvmntow iz'wsfeikl f afs/er y 5 Sheets-Sheet 4 HYDRAULIC GRINDER Flled July 29, 1925 S. EINSTEIN ET AL 1 ilk NN QN NM Sept. 13, 1932.

' 5 Sheets-Sheet 5 Sept. 13, 1932. s. EINSTEIN ET AL HYDRAULIC GRINDER Filed July 29, 1925 2 gears or the like tending to chatter and liable Patented Sept. 13, 1932 I p um'rsosrA'rEs PATENT OFFICE SOL EINSTEIN, F CINCINNATI, AND HERMAN ISLER, 0F NORWOOD, OHIO, ASSIGN- OBS, .BY HESNE ASSIGNMENTS, TO CINCINNATI GRINDERS INCORPORATE), OF CINCINNATI, OHIO, A COBYOBATION OI OHIO HYDRAULIC GRINDER.

Application filed July 29, 1925. Serial No. 46,817.

This invention relates to improvements in grinding machines and more particularly to that form of grinding machine in which the work is normally carried by a table having a transverse or reciprocating movement.

In machines of this type it has been customary to employ either a'rack and pinion or nut and feed screw mechanism for reciprocation of the table. These mechanisms, however, are not entirely satisfactory due to the frequent starting, stopping and reversing actions when the machine isin use. It is therefore, one of the purposes of the present invention to provide a novel and improved means for ejecting such movements of the grinding table.

a A further object of the invention is the provision of a mechanism which is positive in its operation but capable of ready reversing without the employment of clutches, shift to strip or break.

Another object of the invention is the rovision of a table-controlled mechanism 0 extreme smoothness of operation and of means for automatically regulating the speed and di rection of movement of the table.

Other objects and advantages of the presentinvention should be readily apparent by reference to the following specifications taken in connection with the accompanying drawings and it will be understood that any modificationsin the specific details of the construction of the invention and arrangement of the parts within the scope of the appended claims may be made without departing from or exceeding'the spirit of the invention.

Figure 1' is a front elevation of a machine embodying these improvements.

Figure 2 isan end view thereof with parts broken away,

Figuref3 is a fragmentary view'partly in 7 section of the oppositeend of the machine.

45 4-4 of Figure 2.

Figure 4 is a sectional view v on' the line Figure 5 is a-section Figure 4.

Figure 6 is a longitudinal section on the line 66 of Figure 2.

on the, line of Figure 7 is a section of the valve mechanism 7 on the line 7-7 of Figure 5. 1

Figure 8 is a fragmentary view partly in section on the line 8-8 of F1gure 5.- v Figure 9 is a transverse section on the line 9-9 of Figure 1. F j

Figure 10 is a horizontal section on the line 1010 of Figure'9.

Figure 11 is a fragmentary section illustrating the cam control spring, and I Figure 12 is a sectional view of the stopping and reversing member taken on line 1212 ofFigureS). i

In the drawings the numeral 15 designates the bed of a grinder which has been shown as of conventional cylindrical type having the ways 16 for the longitudinally movable table 17 hearing the driven headstock 18 and the tailstock 19 for, supporting a workpiece. Opposed to the table are the ways 20 for the grinding wheel carriage 21 bearing the wheel 22 for operation upon the work. A feed shaft 23 is coupled with carriage 21 for in and out movement thereof through suitable-convene tional gearing. This feed shaft has, at its forward end the manually actuable handwheel 24 and the feed rachet 25. vThis latter is adapted to be advanced in a step by step movement through shifting of pawl 26 by the automatic mechanism hereinafter described.

Carried byv the bed 15 and subtendingthe table 17 is cylinder 27 secured in position by brackets 28 and containing iston- 29 and pistonrod 30. The latter is suitably secured to depending bracket" 31 on the table 17 so ing portion. 35 having inlet passage 36 and exhaust or relief passage 37 and the distributing passages or chambers 38 and 39. A series of valves are provided for controlling the how of actuating fluid within the member 35 ncluding the pressure-reducing valve 40, the

that these parts are constrained to move tocut-oil valve. 41 and the reciprocable distribution-controlling valve member designated as an entirety by the numeral 42. Leading from the chambers 38 and 39 of member are conductor pipes 43 and 44 extending respectively to the heads 45 and 46 of cylinder 27. These chambers 38 and 39 have ports 47 and 48 selectively coupleable with exhaust ports 49 and 50 of chamber 37 or with pressure inlet ports 51 and 52.

s In operation liquid under pressure is forced by pump 32 through pipe 34 into the passage 36. 7 Within this passage is sleeve 53 having a plurality of ports 54 adapted tov register with similar ports 55 of valve 40 when this valve is in open position. Ifthe valve is retated the effective. size of the ports or apertures is reduced, thus cutting down the rate of increase of pressure within the distributing valve casing. The fluid then passes through valve 41 which may be closed if desired to shut off increase of ressure within the casing.

From valve 41 t e fiuid'fiows into a pressure-distributin chamber having the ports 51 and 52' afiordi ng communication with the slide valve cylinders 56 and 57. Ports 47, 48, 49 and50-alsp afi'ordconununication with these cylinders. Slidable within the cylinders are the-ends of the valve 42 which has an intermediately-notched stem or shank portion as at 58 engagingthe lower end of valve-shifting lever 59- which is of less width than the recess and is, therefore, permitted a certain amount-of lost motion in either di- 5 rection priorto actuation of the valve during shifting. The valve has the reduced portions 60 and 61 of extent to couples. pair of opposed ports while-shutting of! communications with the third. Its operation should be clearly understood by reference to Figures 7 and 10 of the drawin s from which it will be noted that in the position shown port 47 is ,the table thus moved inthe reverse direction.

coupled with exhaust port 49 and thus with exhaust pi 62 which leads, the fluid back to tank 31 relieving the pressure in cylinder27. At the same time port 48 of pipe44is coupled through passage 61 .of the valve with pressure inlet port 52 so that presure is introduced into the cylinderthru head 46 tending to shift the piston 29 to the left'in Figurefi.

This action thru pistonrod 30 and bracket 31 will therefore-carry table 17 to the left as is illustrated. Similarly when lever 59 is moved to shift the valve in the opposite direction the connection; of inlet and exhaust ports will; be reversed causin :the pressure to be applied to the oppositeside of the piston and To automatically control the reversing of the valve and thus of the table movement,' the table is provided with adjustable dog.mem-, here 63 and 64 which ma be given a coarse or hand adjustment lengt wise of the face .of the table. The do have the guide ways 65 and 66 for the a justable contacts 67-68 aevmoo of the screws 71-72. Guide ways 65-66 h are so disposed as to loosely receive the roller or contact 73 on valve-shifting lever 74 which is secured on pintle 75 rovided on its inner end with the valve shi ting lever 59. This lever has in addition the cam portions 76-77 co-operating with notches 78 and 79 of shift bars 80, urged together by action of spring 81. The arrangement is such that when one of the members 67 or 68 engages contact 73, lever 74 will be correspondingly rocked while the lower end of connected member 59 moves freely in slot'58 of the valve, cam portion 76-77 separating the two members 80 against force of tension spring 81. As the ends of cam 76-77 move past the center of the tongues 82-83 separating the pairs of notches 78 and 79 the force of spring 81 will rapidly completethe shifting movement of shift lever 59 which by that time is in engagement with the opposite endwall of its recess. This action will actuate valve 42 to operatively associate the opposite pair of ports at each ened from those previously connected re lieving the pressure at one end of thepiston and applying it to the opposite end to reverse the motion of the table.

If at any time it is desired to have the motion of the machine continue to the limit of the piston stroke rather than to be automatically effected on account of engagement of one of stops 67 or 68 with contact 73, this result may be effected by drawing the contact 73 outward against retaining pressure of spring 84.

If preferred to slow up the motion of the table before the end of the stroke and reversal thereof, this may be accomplished by suitable actuation of the pressure control valve 40. In the form illustrated there has been provided a valve stem 85 bearing the eccentric' 86 and the pin 87 engaged in annular groove 88 of plunger 89. This plunger is slidably supported by the bed of the machine having its lower and riding on lever 90 which. is fulcrumed at 91 and upwardly urged by spring 92. The upper end of this plunger has a double beveled portion 93 adapted to be engaged by the inclined or cam portions 7 94-95 of the dogs 63-64 respectively. The manner of operationof this construction will be best understood by reference to Figure 4 by which it willbe-seen that as the dogs move in either direction they will engage the portion 93' of the plunger gradually pressing it downward prior to any engagement with] stop 73. This downward pressure will cause the wall of annular recess 88 to engage and carry downward pin 87 thus partly closing the ports of valve 40 and reducin therate of flow of under pressure into t e cylinder.

and-normally actuate holdthe high point of V {roller- 104. The-line oi -contact I roller and cam issubstantially in the axial 'plane of these .accidentalrotation ofthe cam. On the other Qn reverse movement of the table spring 92 will pull lever 90 and plunger 89 reversely shifting valve 40 so that the full rate of flow produced by the pump may be effective in .the cylinder causing a more rapid movement of the table at the intermediate portion of its stroke, the speed reducing efiect being again produced as the stop dog 64 moves into engagement with the plunger.

The plunger 89 serves a double funct1on,m that it not only controls the slowing down and speeding up of the table movement but also controls the relative feed of the work and grinding member. It has been mentioned that the rotation of feed ratchet 25 is effected by pawl 26. This pawl is pivoted at 96 to bracket 97 on the-upper end of plunger 98, held in position by com ression s ring 99 and adapted to be drawn ownward y interengagement of the end of lever 90 with collar 100 on the lower-end of the plunger. Thus at the completion of the table movement in each direction the downward movement of plunger 89 will rock lever 90 to depress plunger 98 a greater amount due to the greater distance of this plunger from fulcrum 91. This depression will cause a cor-. responding feeding rotation to be applied by ratchet 24 to feed shaft 23. On reverse movement the pawl proper, being gravity actuated, will slide freely back over the ratchet. To govern the amount of feed-for reciprocation of the table an adjusting screw 101 is carried by the bed and slidably received in a recess 102 of bracket 97. While the lower movement of plunger 99 in the mechanism shown is constant its upward movement may be varied as desired by adjusting screw 101. Therefore, the mechanism may be so set that pawl 26 will back over a single tooth or any pie-determined number of teeth of the feed ratchet according to the feeding speed desired.

In some instances it is'advantageous'to be able to permit a very slight additional movement of the table relative to the wheel as for clearing up the face of a shoulder on the work or the like. At the same time it'is necessary that this movement be very accurately regulated and controlled. To facilitate accom-' plishment of this result the table is provided with an adjustable limiting member or stop 103 having contact roller 104 adapted to bear against stop cam 105 preventing further :movement of the table in the direction of the cam even though a continued pressure in this direction be applied to the controlling piston.

Cam 105 is rotatably supported by spindle 106 having the lnanuall controlled wheel 107,

d as by-spring 108' to the cam toward-the between parts so there is no liability of hand the cam may be readily manually rotated in en agement with rol er 104. In this event its ace recedes gradually from its major to-its minor radius permitting a slight movement of the table toward the right as shown; in Figures 1 and 4, the amount of movement of course depending upon the rotation given to the cam. Y 1 To limit the pressure employed, an adjustable pressure-relieving valve 109' coupled with pressure line 34 which will op'en and discharge the fluid under pressure back into the tank through pipe 110 when the pressure is built up beyond the pre-determined safe amount I v From the foregoing description the operation and advantages of the present-invention should be readily understood and it will be seen that there has been provided an -im proved gearless table shifting and reversing mechanism, in which an automatic'reciprocation and reversal of table movement, a variable speed of table movement and a shifting of the table without chatter --or vibration such as is liableto occur with ordinary gearshifting mechanisms is attained. Itwill be further noted that inthe present shifting mechanism there are no parts liable to be damaged by the reversal or injured by undue shifting pressure. f D It will further be noted that the automaticmechanism may be rendered inoperative and the table reversing manually controlled at an intermediate point without infeed of the grinding wheel or at points exterior to the normal feed position without disturbing the setting of the automatic controls.=,An additional advantage presented only with this type of machine is that" the feed of the machine may be checked by inter-engagementof stop members on the fixed and movable parts but thevfeed force continued and one ofthe 7 stop members caused to gradually recede by relatively minute increments and shoulders or the like on the work thus clearedup by slight and controlled grinding action.-

We claim: I n 1. A grinding machine includinga bed, a

table reciprocable onthebed, a wheel carriage movable'on the bedtoward and from' the table, hydraulically actuated means for reciprocating the table during the slowing anism/ for I producing relative transverse 1 andengaging the plunger, mcansyicldingly pressing the lever in engagement with the plunger, and aivalve operatively associated with the plunger and actuated in one direction by positive depressionof the plunger and yieldingly actuated in another direction b the pressure; of the lever against the plimger. I

4. A mechanism of the character described including a bed and a table hydraulically reciprocable on the bed, a plunger carried by the bed, a lever fulcrumed to the bed and engaging the plunger, means yieldingly urging the lever into engagement with the plunger, a valve operatively associated with the plunger and actuated in one direction by positive depression of the plunger and yieldingly actuated in another direction by the pressure of the lever against the plunger, and feed mechanism opcratively associated with the lever for intermittent operation as the plunger is reciproca-ted.

5, A grinding machine of the character described including a bed, a table mounted for reciprocation'upon the bed, a grinding wheel, means for causing a relative feeding movement between the grinding wheel and bed, means for reciprocating the table, and additional means for simultaneously slowing down the rate of movement of the table and actuating the feed mechanism to cause a relative approach of the table and grinding wheel at a predetermined point in the working stroke of the table.

6. A hydraulic grinder including a bed or support, a work table reciprocatable thereon, hydraulic means for reciprocating the table including'a throttle valve, a grinding wheel, means for causing a relative feeding movement between grinding wheel and table, and a single actuator for simultaneously shifting the throttle valve and the feed mechamsm.

-7. A grinding machine of the character described, including a bed or support, a table reciprocatable thereon, a grinding wheel, feed mechanism for causing relative approaching movement between table and grinding wheel, a pair of plungers carried by the bed, means coupling one of said plungers with the feed mechanism, table rate varying means coupled with the other of said plungers, means for simultaneously actuating said plungers in one direction, and independent means for independently actuating the plungers in the opposite direction.

8. A grinding machine of the character described, including a bed or support, a table reciprocatable thereon, a grinding wheel, feed mechanism for causing relative approaching movei'nent between table and grinding wheel, a pair of plungers carried by the bed, means coupling one of said plungers with the feed mechanism, table rate varyingmeans coupled with the other of said plungers, means for simultaneously actuating said plungers in one direction, independent means for independently actuating the plungers in the opposite direction, and an adjustable stop member for limiting the independently actuated movement of one of said plungers.

9. A machine of the character described including a bed or support, a work table reciprocatable thereon, means for shifting the table at a variable rate, a grinding wheel movable toward and from the table, and automatic means for simultaneously variably decelerating the movement of the table and diminishing the distance between table and wheel by in-feed movement of the latter.

10. A grinding machine including a bed or support, a work carrying table mounted for reciprocation thereon, a grinding wheel, means for causing a relative feeding movement betwcenthe grinding wheel and work supporting table, means for reciprocating the table at a variable rate, and dog controlled means for automatically retarding the rate of reciprocation of the table and actuating the feeding means during said retarded reciprocation.

11. A grinding machine including a bed or support, a work carrying table mounted for reciprocation thereon, a grinding wheel, means for causing arelative feeding movement between the grinding wheel and work supporting table, means for reciprocating the table at a variable rate, do controlled means for automatically retarding the rate of reciprocation of the table and actuating the feeding means during said retarded reciprocation, and means for varying the amount of feeding effected by a constant movement ofthefeeding means actuator.

12. In a grinding machine the combination of a bed, a grinding wheel carriage carried thereby and movable transversely thereof, a work supporting table carried by the bed and translatable relative thereto, means for translating saidtable, and means for limiting thetranslation of said table including coacting abutments, manual means for progressively varying the effective position of one of said abutments and automatic means for restoring the abutment to its initial effective position.

13. In a grinding machine of the character described the combination of a bed, a grindtion of the table, means for defining the limit of said zone in one direction including an adjustable stop member carried by one-of said parts and an abutment carried by the other of said parts and having an eccentric surface for engagement with the stop to limit the movement of the table, and means for manually rotating the abutment to present varying portions of its; surface to the stop to variably extend the limit of said zone of movement of the impositively actuated table.

14. In a grinding machine of the character described the combination of a bed, a grinding wheel carriage mounted on the bed and shiftable transversely thereof, a grinding wheel rotatably mounted on the carriage, a table supported by the bed and reciprocable thereon through a given zone past the grinding wheel, means for effecting said reciprocation of the table, a stop member carried by one of the relatively movable parts and provided with a contact roller, a co-operating abutment having an eccentric contact surface disposed in the path of the roller, said stop member and contact roller defining one limit of said zone of movement of the table, and means for imparting a rotative movement to the stop member whereby the roller and member will freely ride in engagement with the other and vary the limit of the zone of movement of the table as controlled by the inter-engagement of said parts.

15. In a grinding machine of the class described the combination of a bed, a grinding wheel carriage mounted thereon for movement relative thereto, a grinding wheel rotatably supported by the carriage, a work supporting table reciprocably mounted on the bed for translation relative thereto past the grinding wheel,.yielding means for reciprocating the table, means independent of the table reciprocating means carried by the bed and table for abutment with one another for limiting the relative movement of the bed and table, and means operative during engagement of the parts for varying the limiting action thereof.

16. In a grinding machine of the class described the combination of a bed, a grinding wheel carriage mounted thereon for movement relativetthereto, a grinding wheel rotatably supported by the carriage, a work supporting table reciprocably mounted on the bed for translation relative thereto past the grinding wheel, yielding means for reciprocating the table, means independent of the table reciprocatingvmeans carried by the bed and table for abutment with one another for limiting the relative movement of the bed and table, and manually actuable means op-' erative during engagement of the parts for varying the limiting action thereof.

17. In a grinding machine of the class described the combination of a bed, a grinding wheel carriage mounted thereon for move ment relative thereto, a grinding wheel r0 tatably supported by the carriage, a work supporting table reciprocably mounted on the bed for translation relative thereto past the grinding wheel, yielding means for reciprocating the table, means independent of the table reciprocating means carried by the bed and table for abutment with one another for limiting the relative movement of the bed and table, and means operative during engagement of the parts for varying the limiting action thereof, said means including a shaft coupled with one of the parts and means for rotating the shaft varying the operative effect of the part.

SOL EINSTEIN. HERMAN R. ISLER.

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